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UNIVERSITY    OF    CALIFORNIA  Agricultural  experiment  Station 

College  of  agriculture  e-  J-  wickson.  director 

BERKELEY,    CALIFORNIA 


CIRCULAR   No.  56 

(August,  1910) 


WORTHLESS    FERTILIZERS 


My  attention  has  from  time  to  time  been  drawn  to  articles  in 
papers  and  periodicals  and  to  advertising  literature,  concerning  the 
alleged  value  of  various  naturally  occurring  rocks  and  mineral  de- 
posits as  fertilizers.  Such  of  these  as  I  have  been  able  to  investigate 
have  been  found  totally  without  merit ;  and  investors  either  in  the 
material  or  in  the  stock  of  companies  designed  to  exploit  the  deposits, 
run  grave  risk  of  financial  loss. 

It  should  be  pointed  out  in  the  first  place  that  few  materials  of 
this  kind  have  any  agricultural  value,  until  they  have  been  refined 
as  in  the  case  of  nitrate  or  potash  deposits,  or  so  treated  as  to  convert 
comparatively  inert  constituents  into  a  form  that  will  admit  of  their 
being  taken  up  by  plants,  as  in  the  case  of  phosphate  rocks.  At 
the  present  time  the  raw  material  for  the  manufacture  of  nitrate  of 
soda  is  found  in  Chile ;  Germany  furnishes  the  potash  deposits ;  and 
the  phosphate  rocks  suitable  for  manufacture  are  found  in  Northern 
Africa,  the  Southeastern  States  and  in  a  section  comprising  the  south- 
western part  of  Wyoming,  the  southeastern  part  of  Idaho  and  north- 
ern Utah.  Up  to  the  present  no  local  deposits  of  any  of  these  materials 
have  been  extensively  utilized  for  manufacturing  purposes.  And 
so  far  as  I  am  aware,  no  such  local  deposits  of  sufficiently  high  grade 
have  been  developed  to  enter  into  competition  with  those  from  the 
above  mentioned  sources. 

The  idea  has  frequently  been  advanced  that  certain  common  rocks, 
notably  those  containing  potash  feldspar,  should  be  of  value  as  fer- 
tilizer because  of  their  content  of  potash.  When  we  consider  the 
relatively  stable  and  inert  character  of  the  complex  silicates  and  the 
further  fact  that  these  are  alread}^  present  in  large  quantities  in 
natural  soils,  it  is  difficult  to  see  how  applications  of  such  materials 
would  result  in  any  immediate  or  important  crop  increase. 

The  well  known  fact  that  lava  rocks  have  frequently  broken  up 
into  fertile  soils  within  a  very  limited  period  is  used  as  an  argument 
to  prove  that  lavas  should  make  a  good  fertilizer.     This,   however. 


does  not  follow.  A  mineral  fertilizer  to^^be^^oii^fe  tire  cost  of  /{ipif)li- 
cation  should  contain  relatively  large  ^m(iujnLtsj§pLo,^  or  Inore  of  the^' 
so-called  ''plant  foods"  in  a  compam^Ciyely  emily^olublC'Co'iiditidn. 
To  furnish  an  amount  of  actual  potash^eqiiivafenf 'tu"that  in  a^ri  ordi- 
nary application  of  sulfate  of  potash  would  require  a  relatively  enor- 
mous quantity  of  ground  lava  of  average  composition.  In  addition 
the  condition  in  which  potash,  the  essential  constituent,  is  combined 
with  the  other  rock  constituents  is  such  as  to  justify  little  hope  of  its 
being  utilized  by  plants  within  a  reasonable  period  of  time.  Potash 
insoluble  in  water,  as  it  occurs  in  such  materials,  has  no  standing 
among  reputable  agriculturists  nor  under  the  laws  of  the  several 
States. 

Exploiters  of  worthless  materials  seem  to  have  two  methods  of 
working:  one  is  by  the  use  of  testimonials  from  real  or  fictitious 
persons  who  are  supposed  to  have  used  the  substances  with  advantage ; 
the  other  is  by  the  quotation  of  chemical  analyses.  The  first  is  subject 
to  all  the  abuses  of  a  patent  medicine  testimonial  and  in  the  second 
case  the  uninformed  investor  is  awed  by  an  array  of  figures  which 
he  does  not  understand  and  cannot  interpret.  Furthermore,  the 
layman  is  apt  to  be  impressed  by  the  reputation  of  the  chemist  who 
made  the  analysis.  This  is  a  grave  error  because  reputable  chemists 
frequently  make  analyses  of  samples  of  material,  the  source  of  which 
is  unknown  to  them.  It  is,  accordingly,  easy  to  quote  a  correct 
analysis  of  a  high  grade  sample  as  applying  to  lots  of  goods  or  de- 
posits which  they  do  not  represent.  Even  well  intentioned  persons 
in  taking  samples  tend  to  select  the  best  specimens  and  fail  to  realize 
that  these  may  not  represent  the  deposit  as  a  whole. 

The  purchaser  of  materials  intended  for  use  as  fertilizer  should 
understand  that  the  sale  of  fertilizers  in  California  is  regulated  by 
law  and  licensed  by  the  State.  All  legitimate  fertilizer  manufac- 
turers and  dealers  handling  goods  not  licensed  by  others  are  regis- 
tered with  the  Fertilizer  Control  of  the  University  of  California. 
For  their  own  protection  consumers  should  see  that  all  goods  pur- 
chased by  them  bear  the  name  and  registry  number  of  the  manu- 
facturer. Attempts  to  sell  unregistered  and  possibly  worthless  mate- 
rials should  be  reported  to  the  Fertilizer  Control. 

The  prospective  purchaser  of  stock  in  companies  designed  to  work 
mineral  deposits  should  bear  in  mind  that,  with  the  exception  of 
high  grade  gypsum,  there  are  few  naturally  occurring  minerals  which 
can  be  profitably  applied  directly  to  the  soil  as  fertilizers  even  when 
finely  ground.  The  manufacture  of  fertilizers  is  a  complex  business, 
requiring  technical  skill  and  for  most  classes  of  goods  considerable 
capital.  No  person  should  buy  stock  of  such  co^ipanies  unless  he  is 
absolutely  sure  of  the  skill  and  integrity  of  the  promoters  and  has 
ex])crt  advice  as  to  the  suitability  of  the  proposed  raw  material  as  a 
constituent  of  fertilizers. 

John  S.  Burd, 

Cheinist  in  Charge,  Fertilizer  Control, 

University  of  California. 


